package com.amos.interview.java.day30;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

/**
 * PROJECT: interview
 * DESCRIPTION: note
 *
 * @author dell
 * @date 2019/3/28
 */
public class Day09 {

    // Complete the factorial function below.
    static int factorial(int n) {
        if (n == 1) {
            return n;
        }
        return n * factorial(n - 1);

    }

    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) throws IOException {
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        int n = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        int result = factorial(n);

        bufferedWriter.write(String.valueOf(result));
        bufferedWriter.newLine();

        bufferedWriter.close();

        scanner.close();
    }

}
